The present invention relates to an integrally molded solid protective casing, or outer barrier of a shin guard, which itself has a enclosed barrier space serving as a buffering room in which air is compressed.
When a player plays in a sport competition, in order to ensure the safety in playing, the player must wear suitable protective equipments such as a helmet, an elbow guard, a shin guard, etc. The existing shin guard generally includes a soft inner lining and an outer protective casing fixed connected with outer side of the inner lining. The inner lining is located on the shin of a user to embrace the shin. The outer protective casing serves to bear the impact of external force so as to protect the shin of the player from being injured by the external force. Most of the existing outer protective casings are made of plastic plate as shown in FIGS. 1 and 2. The protective casing B is combined with the soft inner lining S. Conventionally, the protective casing B is formed with reinforcing concave and convex stripes for increasing the strength against impact force. However, in the sport, the impact always takes place instantaneously and the time for distributing the impact stress is limited. Even though the plastic plate of the protective casing B is formed with concave and convex stripes for increasing the strength against the impact, the impact stress will reversely concentrate on the boundary of the concave and convex stripes formed on the surface of the protective casing B. This makes the protective casing B subject to breakage due to the impact. Therefore, the protection effect provided by the shin guard is reduced.